Friction shock absorbing mechanism



Dec. 7, 1943. G. E. DATH FRICTION SHOCK ABSORBING MECHANISM -Filed 001;. 6, 1941 sss a Patented Dec. 7,` 1943 FRICTION SHGCK MECHANI George E. Dath, Mokena, Ill., assignor to W.

H. Miner, Inc., Delaware Chicago, Ill., a corporation of Application October 6,1941, SeralNo. 413,79

7 Claims.

This invention relates to improvements in friction shock absorbing mechanisms.`

The main object' of the invention is to provide a friction shock absorbing mechanism comprising a friction casing, a friction clutchA having sliding frictional engagement with the casing, and spring resistance .means yieldingly opposing movement of the clutch inwardly of the casing, wherein the clutch includes a central wedge block and friction shoes surrounding the block, and the parts of the mechanism are held assembled by shouldered engagement of the wedge with the casing, outward movement of the wedge thus being limited and the wedge, in turn, limiting outward movement of -the shoes by engagement therewith.

A more specific object of the invention is to provide a friction' shock absorbing mechanism comprising a friction casing open at its front end only, and having interior friction surfaces,a plurality of friction shoes having sliding frictional engagement with the friction surfaces of the casing, spring means within the casing opposing'inward movement ofthe shoes, and a wedge block having wedging engagement with the shoes tov spread the same apart, wherein the wedge is provided with retaining lugs adapted to engage shoulders on the casing to limit outward move-v ment of the wedge and wherein theparts are so designed that the wedge, shoes and spring resistance may'be assembled with thev casing by entering the same through the open front end of l 'the casing, thereby making it possible to use a one-piece casing structure having the rear end closed by a permanent wall member integral with the casing side walls.

Other objects of the invention will more clearly appearfrom the description and claims hereinafter following. y

In the drawing forming a part 'of this specification Figure 1 is a longitudinal sectional view through a friction shock absorbing -mechanism illustrating my improvements in connection therewith, said view corresponding substantially to the line I-I of Figure 2. Figure 2 is a front end elevational view of Figure 1, as indicated by the'arrows 2-2 of Figure 1. Figures 3 and 4- are transverse sectional views, corresponding reF spectively to the lines 3-3 and 4 4 of Figure l.

As shown in `saidndrawing my improved fric-a tion shock absorbing mechanism"4 comprises broadly a combined frictional shell and spring cagel A, a Wedge B1having anchoring means in shouldered engagement with the combined shell lugs I6 are so arranged tion, havingthe friction shell section formed at 4the forward end and the spring cage section at the rear end thereof. The casing A is closed at the rear end by a transverse wall Ill formed integral with the side walls thereof. The friction shell section of the casing is provided with six,

interior, vsubstantially flat, inwardly converging friction surfaces II which are spaced symmetrically'about the central longitudinal axis of the mechanism. The friction surfaces II are arranged in pairs, the adjacent surfaces of each pair together forming a friction face of V'-shaped transverse contour; At the open outer end'the casing A is provided with three internal stop lugs I2I2I2 which are alternated with the three pairs of friction surfaces II-I I, the same being located between adjacent of said V-shaped fric-v tion faces which are formed by the pairs of surfaces II-I I.

The wedge three radially projecting, equally spaced, circumferential flanges I3-I3-I3 'a't its outer end.

The outer faces of the flanges I3 lie in the samev planeeas the outer end of the block and together Awith said outer end form aflat surface I4 lying in a single plane. At the inner end portion thereof the block B is provided with three nat wedge faces I5-I5.-I5, arranged symmetrically about the longitudnial central axis of the wedge. The three faces I5 converge inwardly or rearwardly of the mechanism. Rearwardly of the wedge faces I5 the block B has threey laterally outwardly projecting radial lugs 'I6-I6-I6, which are-alternated with the Wedge faces as clearly shown in Figure '4. In other words, the that they are located between adjacent wedge faces and extend between adjacent sho s C to engage 'in back of the lugs I2 of the casing and restrict outward movement of the wedge. v

The-three friction shoes C-C-C are of similar design, each shoe having an outer, longitudinally extending V-shaped friction fa'ce formed by two l adjacent angularly arranged friction surfaces I1-'I1 which arev adapted to cooperate with one Aof said pairs of friction surfaces II-I I, and Aare correspondingly inclined to said 0f the block B and correspondingly inclined Bis inthe form of a blockrhaving thereto. The inner ends of the enlargements I8 of the shoes present flat transverse abutment faces 20 on which the spring resistance D is adapted to bear. At the forward end portion of each shoe C, one side edge thereof is notched or out away as indicated at 2| to provide clearance to facilitate application of the Wedge B to the shock absorbing mechanismv in the assembling operation ad hereinafter pointed out. As shown most clearly in Figure 2-the cut away portions are on corresponding side edges of the shoes and each cut away portion is of a width slightly greater than the width of one of the lugs I6 of the wedge B.

The spring resistance D, as shown, comprises a single coil bearing at its front end on the rear faces 29 of the enlargements I8 of the shoes, and bearing at its rear end on the rear wall III of the' casing A. This spring is preferably under slight initial compression. l

In assembling the mechanism, the spring D first placed within the casing A. The shoes C-C-C are then assembled with the casing and are forcedinwardly until the recessed lsections 2| thereof pass inwardly beyond the lugs I2 of the casing to a position wherein the lugs I5 of the wedge B will pass freely between the lugs I2 and the inner end walls of said recesses 2|.

With the shoes held in this position the wedge B is inserted between the shoes C-C-C by first aligning the lugs I6 of the wedge B with the notches 2| of the shoes, then pushing the wedge inwardly until the lugs I6 are disposed inwardly and clear of the lugs I2 of the casing, and then giving the wedge a partial rotation to the right as viewed in Figure 2, to bring the` lugs I6 in back of the lugs I2 in aligned position with the latter. faces I5 thereof are in registration with the faces I 9 of the shoes to flatly engage the latter. When e the parts have been brought to this position the' mechanism, the spring resisted friction shoes are wedged apart. and carried inwardly of the mechanism compressing the springA D thus producing high frictional resistance between the frictionsurfaces of the shoes and the casing. wUpen the actuating force being reduced the expansive ac- .tion of the'spring returns all of the parts to the normal position shown in Figure 1, the wedge being limited in its outward movement by engagement of the lugs I8 thereof with the lugs I2 of In this position of the wedge B the wedge open end; of a friction clutch cooperating with said casing; and a spring opposing inward movement of said clutch, said clutch including a wedge block and friction shoes surrounding said block, said -block having radial lugs extending between adjacent shoes and into shouldered engagement 1 with the lugs of said casing to Alimit outward movement of said block.

2. In a friction shock absorbing mechanism, the combination with a friction casing open at the front end and closed at its rear end, said casing having interior friction surfaces at said open end, said casing having inturned lugs'at said open front end; of a wedge block having wedge faces, said block having laterally outwardly projecting lugs at its rear end engageable in back of the lugs of the casing tlimit outward movement of the wedge, said wedge being rotatable about its longitudinal axis to bring the lugs thereof intov and'out ofregistration with the lugs of the cas'- ing; friction shoes surrounding said wedge, said shoes having friction surfaces engaging the casing friction surfaces, and wedge faces in wedging engagement with the wedge faces of said block; and means within the casing yieldingly opposing inward movement of the shoes.

3. In 'a friction shock absorbing mechanism,

the combination with a friction casing open at its front end and closed by a transverse wall at the rear end,said casing having interior frictionv surfaces at said open end and a. plurality of inturned retaining lugs at the front end of said fraction surfaces; of a wedge block having wedge faces, said block having laterally outstanding lugs engaging in back of said lugs of the casing to restrict outward movement of the wedge: 4shoes interposed between the Wedge and shell friction surfaces and having wedge faces engaging the wedge faces of said block, said lugsl extending lbetween adjacent shoes; and a spring within the casing interposed between the shoes and the rear wall of the casing, said spring yieldy ingly resisting movement of the shoes.

4. In a friction. shock absorbing mechanism, the combination with a friction casing open at the front end and closed by a transverse wall at the rear end, said casing having interior friction surfaces at said open end, said casing having a plurality of inturned retaining lugs at said operi end; of a wedge block having a plurality of outwardly extending retaining vlugs corresponding in number to the lugs of the casing and engageable therewith; a plurality of friction shoes interposed between the wedge block and casing, friction surfaces, said block and shoes having cooperating 'wedge faces, said lugs extending between adjacentv shoes; and a spring within, the casin'g yieldingly resisting movement of the shoes inwardly of the casing. f

.5. In a friction shock absorbing mechanism,

^ the combination with a friction casing open at the casing, and the shoes being, in turn, limited.,n

1.,In a friction shock absorbingmechanism,

the combination with a friction casingopen at one end, said casing having circumferentially spaced, laterally inwardly projecting lugs at said the front end, said casing having three interior friction surfaces, said casing having three inturned retaining lugs at the -open end thereof,

said lugs being disposed respectively -between A 'adjacent friction surfaces; of three friction shoes respectively engaging said friction surfaces, said shoes having wedge faces on their inneiY sides: a wedge block having three retaining lugs extending between adjacent friction shoes and engaging with the lugs ofthe casing to limit outasaltan for the corresponding lugs of the wedge when said wedge is rotated to an extent to clear the lugs of the casing; and spring means within the casing opposing inward movement of the shoes.'

6. In a friction shock absorbing mechanism, the combination with a friction casing open at the front end and having three V-shaped interior friction surfaces at said front end arranged symmetrically about the longitudinal Acentral axis of the casing, said casing having inturnedretaining lugs at-said front end alternated with said friction surfaces; of a friction shoe cooperating with each of said V-shaped casing surfaces. each shoe having a wedge face on its inner side; a wedge block having wedge faces respectively engaging said shoe wedge faces, said block having radially outwardly projecting retaining lugs lextending between'adjacent shoes and cooperating with said casing lugs to limit outward movement of the block; and means within the casing yieldingly opposing inward movement of the shoes.

7. In a friction shock absorbing mechanism.

- the combination with a friction casing open at the front end, said casinghaving longitudinally extending interior friction surfaces at saidA front end, said casing having inturned retaining lugs 'at said front end alternated with said friction surfaces; of a plurality of friction shoes cooperating with said friction surfaces, said shoes corresponding in number to said friction surfaces: a wedge block between said shoes having wedging engagement therewith, said wedge block having radially outwardly extending retaining iugs extending between. adjacent-...shoes and engaging with the lugs of the casing to limit outward movement of the wedge, each shoe Ahaving one side edge thereof cut away at the forward end thereof, said cut-away portions being on corresponding sides of the shoes and providing clearance for the lugs of said wedge in assembling the wedge with the other parts of the mechanism when said shoes are displaced inwardly to a predetermined extent and said wedge is rotatably displaced to bring said lugs in alignment with said cut-away portions of the shoes -and clear of the lugs of the casing; and means 

